Hemoglobin decline as a signal for hyperprolactinemia onset prior to prolactinoma diagnosis in hypogonadal men.

In our cohort of men with prolactinomas and hypogonadism, we found a marked decrease in HB levels that preceded prolactinoma diagnosis by a median of 6.1 years, with a mean delay of 4.1 years between HB decrease and hypogonadal symptoms appearance. These results suggest that HB decline prior to prolactinoma diagnosis may serve as a marker for hyperprolactinemia onset in a subset of hypogonadal men and allow a more accurate assessment of disease duration.